js
 |-base
    |_sprite.js （没有用到）
 |-entity
    |_square.js
    |_squarefactory.js
 |-libs
    |_symbol.js
    |_weapp-adapter.js
 |-runtime
    |_background.js
    |_databus.js
 |_main.js
game.js
game.json
project.config.json

    canMove(type){
        let y = this.current.anchor.x
        let x = this.current.anchor.y
        let index = this.current.index
        let data;
        switch(type){
            case 'down':
                x += 1
                break;
            case 'left':
                y -= 1
                break;
            case 'right':
                y += 1
                break;
            case 'change':
                index = (index + 1) % 4
                break;
        }
        data = this.current.data[index]
        // 是否可以向左
        for(let xIndex = 0; xIndex < data.length; xIndex ++){
            for( let yIndex = 0; yIndex < data[0].length; yIndex ++){
                if( data[yIndex][xIndex] == 1 && (x + yIndex >= 20 || y+xIndex >= 10 || y+xIndex < 0 || this.gameData[x+yIndex][y+xIndex] == 2)){
                    return false
                }
            }
        }
        return true
    }

    touchStartEvent( touch ){
        if(!this.current.canDown){
            return;
        }
        if( touch.screenY < this.downArea){
            return;
        }
        if( touch.screenX < this.leftArea) {
            this.left()
        }else if( touch.screenX < this.rightArea){
            this.change()
        }else{
            this.right()
        }
    }

判断 this.touchMove 中第一个点和最后一个点的 y 坐标差

    wx.onTouchEnd( (data) => {
        if(this.touchMove.length < 2){
            return
        }
        let first = this.touchMove[0]
        let end = this.touchMove[this.touchMove.length - 1]
        if( end.screenY - first.screenY > 100){
            this.fall()
        }
        this.touchMove = []
    })
    wx.onTouchMove( (data) => {
        this.touchMove = this.touchMove.concat(data.touches[0])
    })